Pilot valve



1951 D. G. GRISWOLD 2,564,529

PILOT VALVE Filed May 21, 1945 7 Sheets-Sheet 1 flaw/d 6: 6111110010 14, 1951 D. G. sRgswoLo 2,564,529

PILOT VALVE Filed May 21, 1945 7 Shee't's-Sheet 5 fiozzaldfi. 6111920010 g- 14, 1951 I D. G. GRISWOLD v 2,564,529

I PILOT VALVE Filed May 21, 1945 '7 Sheets-Sheet 4 Aug. 14, 1951 D. G. GRISWOLD 2,564,529

PILOT VALVE Filed May 21, 1945 '7 Sheets-Sheet 5 Aug. 14, 1951 D., G. GRISWOLD PILOT VALVE '7 Sheets-Sheet 7 Filed May 21, "1945 M W M m J Patented Aug. 14, 1951 UNITED STATES PATENT OFFICE PILOT VALVE Donald G. Griswold, Alhambra, Calif. Application May 21, 1945, Serial No. 595,006

6 Claims.

This invention relates to novel pilot valve constructions of general utility adapted to control the supply and exhaust of operating fluid to miscellaneous apparatus, such as a pressure fluid operable main valve or valves, a fluid pressure operable cylinder and piston, etc. The invention further relates to novel methods of making certain of the elements of the pilot valves.

The principal object of the invention is to provide a pilot valve unit which is relatively simple in construction, has but a few parts that can be quickly assembled, and which requires only a very slight force to operate.

Another object of the invention is to provide a pilot valve of small size having the ports thereof arranged so as to provide for a maximum of flow, thus assuring quick operation of the apparatus controlled thereby.

A more specific object of the invention is to provide a pilot valve construction consisting primarily of stamped or drawn sheet metal parts.

Another object of the invention is to provide a pilot valve unit that may be adapted to control various fluid pressure operable devices by varying the porting of a fluid distribution base member which is assembled therewith.

Another object of the invention is to provide a pilot valve unit that may be readily associated with any suitable operating means such as an arm,' a float or other means for operating said arm, a rack and pinion, etc., for effecting actuation of the movable element of the pilot valve.

Another object of the invention is to provide a control unit including the present pilot valve and a pressure-responsive device for actuating the pilot valve, all in a single assembly.

A further object of the invention is to provide a relatively simple method of making a multiported rotatable element for use in a pilot valve, or the like.

A still further object of the invention is to provide a relatively simple method of makin a ported base member having a seat cooperable with a rotatable multi-ported disc element or the like.

Other objects and features of the invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which:

Fig. 1 is an enlarged elevational view of the drive-shaft end of a pilot valve unit constructed in accordance with the principles of the present invention;

Fig. 2 is an enlarged elevational view of the base-end of the pilot valve unit shown in Fig. 1;

Fig. 3 is an enlarged horizontal sectional view through the pilot valve unit taken on the line 3-3 of Fig. 2;

Fig. 4 is a perspective view of the pilot drive shaft and drive washer;

Fig. 5 is a perspective view of the cup and disc comprising the rotatable pilot element, and particularly illustrating the indexed relationship of these parts prior to assembly;

Fig. 6 is a sectional view showing the disc after it has been sweated to the undepressed portions of the bottom wall of the cup, and after the cup has been partially filled with lead, but before any ports have been drilled through the bottom wall and lead core;

Fig. '7 is a plan view of the completed rotatable pilot element;

Fig. 8 is a plan view of the gasket per se which is interposed between the pilot valve housing and base member;

Fig. 9 is a plan view of the disc per se which forms a seat for the rotatable pilot element;

Fig. 10 is a plan view of the pilot base per se, particularly illustrating the relationship of the various ports and passageways which are formed therein;

Fig. 11 is a somewhat schematic view, partly in section, illustrating the manner in which a control unit including a pilot valve and a pressureresponsive device for actuatin the same may be associated with a conventional diaphragm valve to make the said diaphragm valve act as a pressure relief valve;

Fig. 12 is a fragmentary plan view of the control device shown in Fig. 11 with portions broken away to illustrate the manner in which rotation of the pilot drive shaft is effected by the pressureresponsive device;

Fig. 13 is an enlarged sectional view taken on the line I3'|3 of Fig. 12;

Fig. 14 isa plan view of a seat disc;

Fig. 15 is a plan view of a modified base member per se, as viewed on the line l5'l5 of Fig. 13, with a seat similar to that shown in Fig. 14 indicated in dot-and-dash lines;

Fig. 16 is a sectional view taken on the line I6--I6 of Fig. 13 and particularly illustrating the porting of the sub-base or fluid distribution base member;

Fig. 17 is a plan View of the gasket per se which is interposed between the base and sub-base members as viewed on the line I1I| of Fig. 13;

Fig. 18 is a diagrammatic view showing the relative positions of the porting of the sub-base and rotatable pilot element of Fig. 13 corresponding 3 to the open position of the pressure relief valve;

Fig. 19 is a similar view but showing the rotata'ble pilot element in a position to effect closin of the relief valve; and

Fig. 20 is a sectional view through a modified form of base member.

Referring now to the form of the invention shown in Figs. 1 to 10 of the drawings, the pilot valve unit is generally identified by the letter P and comprises a fluid distribution base member I (see Fig. '3) which is provided with "six miles 2 extending therethrough. The base I is preferably made of brass or other relatively non-corrodible material and one face thereof is provided with a recess 3 for the reception of an annular rubber gasket 4. A hollow housing 5 made (if stamped or drawn sheet brass comprises a radially extending flange portion 6 which engages one face of the gasket 4 and terminates in a longitudinally'ex= tending flange I overlapping a portion of the periphery of the base i. The flange 6 is provided with six holes'il aligned with the holes 2 of the base I, and the gasket 4 is provided with six correspondingly spaced holes 9. Brass bolts extend through each of the holes 8 inthe flange 6, the holes 9 in the gasket 4 and the holes 2 in'the base I, and brass nuts II are threaded onto the bolts l0 and maintain the housing, gasket and base in assembled relation.

The housing (-Fig. 3) also includes a generally cylindrical wall portion I2 which provides a pressure chamber I3 within the housing adjacent the base i. The wall portion l2 tapers in wardly intermediate'o'f its length as indicated at [4, andthen extends longitudinally as indicated at |5to providea-cylindrical chamber I6, the wall l5 being offset to provide an external shoulder f1 and an internal-shoulder l8. The'housing' 5 still furtherfincludes an end Wall 19 provided with acentral aperture 20 through which a pilot drive shaft2l extends. A plug member 22 isdisp'os'ed in the chamber [6 and has a central opening'23 serving as a journal for the shaft'ZI. The plug 22- 'includes an enlarged head-portion 24 which seatsagainst the shoulder l8 with its periphery having a pressed-fit engagement with the inner surface of the wall l5 to retain'the plug in place. The plug 22 is preferably m'adeof brass'and has a reduced longitudinally extending portion 25' which terminates at the end wall l9 or the hous= ing 5. The extended portion 25 of the plug 22 is counterbored' as indicated alt-26 for the reception of a conventional ring-type rubber packing 21 which in its'free state isnormally circular in cross sectionand adapted to prevent leakage of operating fluid from the pressure chamber I 3 along the'shaft' 2 I A cup-shaped cap 28, formed of stamped or drawn: sheet brasa'includes a generally cylindrical wall 29 which snugly engages the 'outer=sur-' face of thewall l5 and has its lower edge seated upon the shoulder H. The cap 28 is-prefera'bly secured to the housing-*5 by solderas' indicated at 30. The cap 28 has a central opening 3| formed in the end Wall 32 thereof-and'the pilot'drive shaft 2I=1projectsthrough said opening and slightly beyondsaid endwall. Theshaft' 2 l' maybe rotated by'any suitable means-and-in Figs. 1, 2 and'3; a brass arm 33 has been shown for this purpose.

One end of the arm-33 has-an opening-":3 to receive the shaft 21 and said armis fixed to said shaft by a screw pin 34 threaded'into'an opening 34 in' saidarm andprojecting through an opening 35 in said shaft. The cap 28 is provided'with an elongated-slot 36 through which'the arm 33 extends and an aperture 31 positioned diametrically opposite the slot 36 affords means through which the screw 34 may be inserted for mounting in the arm 33 to secure said arm to the shaft 2|. The slot 36 is of such arcuate length as to permit the arm 33 to swing through an angle of 30 to either side of a horizontal line passing through the center of the shaft 2|, as indicated in Fig. 1, to accommodate the necessary angular movement of a rotatable pilot element R; as will be" pfiinted out in greater'detail hereinafter.

i'he shaft 2! extends through the plug 22 and into the pressure chamber [3 and its inner end is provided with a series of longitudinally extending serrations or flutes 40. The shaft 2| is preferably made of stainless steel and the fluted 'end thereof is forced into a central opening 4| in a drive washer 42. The drive Washer is best illustrated in Fig. 4 and consists of a generally circular brass stamping provided with three notches '43: spaced approximately 'l-20-'ap'art and defined by arcuate surfaces 44 and'radially ex tending walls 45.

The drive washer 42 is adapted to bepperatively engaged with the rotatable pilot element R, previously referred to. The element'R con sists of a stamped'or drawn brass cup46 '(Figs. 3, 5, 6 and '7) having aside' wall 41 provide'dwith longitudinally extending projections 48 which are adapted to be received in the notches-4 3 of the drive washer "42. The sides "48 of the projections 48 are adapted to be"engag"ed'by the'radially ex tending walls 45 of the drive washer' i2 so-th'at rotary movement of the drive Washer 42 is'accompanied by corresponding rotary moverfient of the cup 46.

The cup 46' has a bottom wall 49 whose-exterior surface is smooth except-for three radially '-ex= tending exhaust grooves in depressions 50, 151 and'52 which mergeat their inner'ends and are formeddur'ing the stamping operation byfor'cing portionsof said-bottom ivall'inwardly. The grooves 59; 5| "and 52- are-arranged upon radii spaced 120 "apart, as will be "apparent from Fig. 7.

A disc 55 (Fig.5) isprovided'with"'a central exhaust port fid' and sixhol'es 67,58, GSMTQ H and 12 arranged upon radii spaced apart. Infabricating the disc 55; thes'an'ieisprefer ably punched from a strip -of "s'tainaless' ste'eland the port 66 and holes 6'1 tol2 are formed byva punching operation. Thisprovides" 9 "heap' 'an'd inexpensive way of produclng'the'disc '55. The perforated disc '55 is secured to the bottom wall 49 0f the cup 46 inany suitablemanner, but is preferably sweated onto the undepress'ed poitions of said bottom wallby 'a conventional bondirig mediumQ- as indicated in Fig. 6,- the'disc 55 first beingindexedwith the cup" 46 so that the holes 61, 69 and H communicate 'with zthe outer ends-of-the exhaust grooves-'55,: 5i and 52, respectively. After the disc 55 hasbeen secured to the; bottom wall of the" cup' -45, said cup is partially filled with molten metal preferably lead, to weight the same, and after the lead has solidified pressure ports 68*, 10 and 'lfl (Fig. '7) are drilled throughthe'bo'ttom walt 49 and thelead core or-body' using the-holes 58, 'H) and 12 of the disc 55 as a guiderandithus utilizing the disc- 55 as a template. Fig-'6 indicates the location of the-pressure port -'|2- dot and dash lines in alignment with .the 'hole' 72 of the disc 55. The pressure ports fil 18 and 12 are disposed intermediate the holesiBl, and 'H,'which cooperate with'the' grooves153,

5| and 52 to function as exhaust ports. The upper surface of the lead core 13 is then provided with a central counterbore I4 (shown in dot-and-dash lines in Fig. 6) to form a seat for one end of a compression spring l5 (Fig. 3). The outer surface of the disc 55 is ground, if necessary, and then lapped to a smooth finish.

The base member I (Figs. 1, 2 and 9) is provided with a radially extending opening 16, which is threaded at its outer end for the reception of a conventional fitting I? having a supply tube or conduit I8 connected thereto. A port I9 at the inner end of the opening 16 communicates with the pressure chamber I3 of the housing 5 and serves to admit operating fluid under pressure into said chamber from the supply tube I8. The base member I is further provided with radially extending openings 80 and 8| which are threaded at their outer ends and merge into radial-passageways 66 and 69 respectively, at their inner ends. A stainless steel stamped and punched disc 83 (Fig. 9), in all respects identical to the disc 55, is provided with an axial exhaust port 86 and six holes 61 68 69 18 TI and 12 arranged upon radii spaced 60 apart. The disc 83 is indexed upon the inner face of the base member I, as

indicated in dot-and-dash lines in Fig. and is then secured to said base member, preferably by a conventional sweating operation. After the disc 83 has been sweated onto the base I, the hole 69 is used as a guide for drilling an axial exhaust port 86 in the base I and this port communicates with the inner end of the passage 66. The hole 39 is also used as a guide and a port 69 is drilled in the base I and communicates with the inner end of the passage 69 so that the disc 83 is also utilized as a template. After the ports 66 and 69 have been drilled in the base I, the outer surface of the disc 83 may be ground, if necessary, and then lapped smooth to form a seat for the lapped disc 55 carried by the rotatable member R.

When the pilot valve unit P is to be used for controlling the supply and exhaust through a single working conduit, no additional ports need be drilled in the base I in alignment with any of the remaining holes of the disc 83. However, if the pilot valve unit is intended to control the supply and exhaust through, say, two different conduits, then an additional opening 8N and a passage 68 may be formed in the base, as indicated in dot-and-dash lines in Fig. 10, and a port 68 communicating with the passage 68 may be drilled using the hole 68 in the disc 83 as a guide. Additional openings, passages and ports (not shown) may be provided in the base I using the remaining holes, for example, holes 61 and 10* as guides, if desired. The base I is preferably a brass casting, and it will be understood that as many as six openings like the opening 16, for example, may be formed by cores and that radial passages, such as the passages 66 68 and 69 and ports, such as the ports 66, 68, 89 and I9 may be drilled as desired, depending upon the means to be controlled by the pilot valve.

A conventional fitting 84 (Figs. 1 and 2) is threaded into the opening 80 and one end of a drain tube or conduit 85 is connected to said fitting. Another conventional fitting 86 is threaded into the opening 8| and one end of a working tube or conduit 81 leading to a device (not shown) to be controlled by the pilot valve, is connected to said fitting.

In manufacturing the pilot valve unit shown in Fig. 3, it will be obvious that the various elements comprising the same may be mass produced at comparatively low cost. In assembling the pilot valve, it will be apparent that the housing stamping 5 and the cap stamping 28 may be telescoped with the end of the side wall 29 of said cap abutting the shoulder I! and the parts permanently secured together by the solder 30. The plug 22 with the packing 21 seated in the counterbore 26 may be then force-fitted into the chamber I6 with the head of said plug seated against the shoulder I 8. The fluted end 40 of the shaft 2I is forced into the opening M of the drive washer 42 to permanently secure these parts together. A semi-hard brass thrust washer 90 is slipped over the end of the shaft 2| and the shaft is passed through the opening 23 in the plug 22 and through the opening 20 in the housing 5 and into the cap 28. The inner end of the arm 33 is then inserted through the slot 36 and the shaft 2| projected through the opening 33 in the arm, the shaft being advanced until the opening 35 is aligned with the screw hole 34 in said arm, and then the screw pin 34 is inserted in the opening 35 through the cap opening 3! to fix the arm 33 onto the shaft 2|. The spring is then seated in the counterbore 14 of the rotatable element R and the projections 48 on the cup 46 are positioned so that they engage in the notches 43 of the drive washer 42. The gasket 4 is then positioned in the counterbore 3 of the base I and placed in con-v fronting relation to the inner face of the flange 6 of the housing 5. The disc 55 is now lightly urged into engagement withthe seat disc 83 by the spring 15. There is sufficient play between the projections 48 of the cup 46 and the notches 43 of the drive washer 42 to enable perfect seating of the lapped surfaces of the discs 55 and 83. The bolts II) are then passed through the flange 6, gasket .4, and base I and the nuts I0 are then threaded onto the bolts to complete the assembly. The conventional fittings TI, 84 and 86 may then be mounted in the threaded openings I6, and 8|, respectively. The supply tube 18 is then connected to the fitting i1 and the drain tube 85 is connected with the fitting 84. The working tube 81, which has one end connected with a pressure operable device (not shown) is then connected at its other end with the fitting 86, and the pilot valve is ready for use.

The arm 33, as has been previously stated, travels through a total angle of 60. Assuming, as an illustration, that the pilot valve P has the arm 33 associated with a float (not shown) through a rod 9| (shown in dot-and-dash lines in Fig. l) for controlling the level in a water storage tank (not shown) and that a fluid pressure operable valve (not shown) is connected with the working conduit 81, so that the same is controlled by the pilot valve P, the raised position of the arm 33 (indicated in dot-and-dash lines in Fig. 1) will then correspond to a positioning of the pilot element R relative to the base member I', such that operating fluid under pressure will be admitted to the fluid pressure operable valve (not shown) to effect closing thereof and, conversely, when the arm 33 is in its lowermost position (shown in full lines in Fig. 1) the pilot element R will be positioned to exhaust operating fluid from such valve to permit the same to open and fill the tank. The converse will be true when the arm 33 is down and the fluid pressure operable valve (not shown) will be closed, all as 7 will-be .readily understood' by those familiar with the art.

It will be observed that when .the arm 33 is in its lowered position, the rotatable element R will-assumeaposition relative to the .base I indicated in Figs. 2 and 3. Upon reference to these :figures, .it will .be observed :that .the exhaust groove 5I .establishes communication 'between .the working tube .851 and .the exhaust tube 85 through passage Ga'. ,-.port 169, holes :fifl and 0.9,.exhaustgroove I, exhaust ports 65, :06" and 66 and passage.66 ,.lso that spentoperatin'gfluid can be exhausted from tube .8] through the pilot valve P and. discharged through the. drainttube 85.

'Whenthearm 331is movedto its raisedposition, the rotatable element -R will have :been turned through an angle of'SO .in a counter-clockwise direction, as viewed .in Fig. =2. This will position the pressure port .11! of the element iRin alignment with the port:69 of the .base I so that op.- erating :fluid under pressure can then pass from the pressurev chamber I 3 into .port 69 and passage 0.9. and into tube 3.1 to actuate the ,device (not shown) to becontrciled.

It will be apparent from the foregoingdescription that the through-ports .88 and :72 per-form no function with'the particular porting of the base 1 shown and could be omitted, if desired. The .same is true .of the exhaust grooves 50 and 52, .and these could also :be omitted, if desired. However, in order to adapt the rotatable element R to perform a maximum number of control op era-tions it is preferable to include the ports I58 and I2 and grooves 50 and 52, it being understood that thegrooves 50, 5 land 52 are all formed at the time that the cup .46 is'stamped and italso being understood that the through-ports 68 .10? and 12 are preferably simultaneously formed by amultiple drilling operation.

Referring now to Figs. 11 to 18, the pilot valve P" here shown is similar to that illustrated in Fig. 3, but includes modified base elements and is shown in association with a pressure-responsive device X and a diaphragm-type pressure relief valve V connected in a pipe line L. The corresponding parts have been identified by the same reference numerals in order to avoid repetition of description. The modified pilot valve P in.- cludes a cast brass base member 92 which is best illustrated in Figs. 13 and As here shown, a stainless steel disc stamping 93 "(shown in dotand-dash lines in Fig, 15) similar to the disc 83, is'secured to the-inner face of the base 92 preferably by a conventional sweating operation. The disc 93 is provided with a central exhaust hole 94 and sixaddi'tional holes 95, 96, 91, 98, 0-9 and I00 (Fig. 14), arranged on radii spaced 60 apart, and these holes serve as guides for drilling seven ports 94=- to I03 (Fig. 15-) in the base member 92 in alignment therewith. The last-mentioned ports register with passages 94 to H10? (Fig. 1 -7), respectively, formed in a suitable rubber gasket IGI. The gasket l0I is interposed between the base member 92 and a cast brass, sub-base or fluid. distribution meniber I02.

The details of the porting and passages of the base 02 are best illustrated in Fig. 16. It will be noted from this figure, that the base I02 is provided with a central drain port MHwhich communicates with an opening I03 threaded at its outer end and merging at its inner end with a passage 94*, The outer end of'the opening I0; is threaded to receive a conventional fitting IE4 having a drain tube I95 connected thereto. The base I02 has another opening I06 which is threaded at its outer end, and a pressure fluid supply port I0'I extends inwardly from the inner face of said base and communicates with the inner end of said opening. A conventional fitting I08 is mounted in the opening I06 and one end of a supply tube I09 is connected to said fitting, the other end III) of said tube communicating with the inlet opening of the pressure relief valve V, as shown in Fig. 11. The'port I0! is aligned with a passage III in the gasket IOI which in turn is aligned with a passage H2 in the base 92 so that operating fluid under pressure can be conducted to the pressure chamber I3 of the pilot valve P from the-supply tube I09.

The base I 02 has two arcuate grooves I I3 and H4 rabbeted in its inner face with the grooves I I 3-and II4 interconnected at a point coinciding with a port II5, and with the opposite ends H6 and III of thegrooves spaced 120 from theport H5 and from each'oth'er. The port H5 and the groove terminals H6 and II-I are arranged so that they register with the passages 91 and and 99, respectively, formed in the gasket -IOI so that the 'ports 95*, 91 and 99 in the base 92 are adapted to be in constant communication with thegrooves 'I I3 and H4. The port II5 com-' municates with the inner end of an opening I 10 through a passage H9. The outer end of the opening H8 is threaded and has a conventional fitting I20 mounted therein. A tube I2I has one end thereof connected to the fitting I20 and the opposite end I22 (Fig. 11) of said tube is connected with the valve V so as to communicate with the diaphragm chamber therein.

The operation of the pilot valve P is the same as that of the pilot valve P, except that the rotation of the pilot element R, is effected by ac,- tuation of a brass spur gear I25 secured to the shaft 2| by a screw I25 and a stainless steel rod I20 adapted to serve as a rack, instead of through the arm 33, the rack I26 being in the form of a rod associated with the pressure-responsive device X, as will be described more fully hereinafter.

As illustrated in Fig. 11, the pressure-responsive device X includes housing sections 1.31 and I82, which preferably are cast'of "brass or other corrosion-resisting material. A flexible diaphragm' I33 is interposed between the housing sections I-3I and I 32 and these parts are held in assembled relation by six bolts I '34. The housing section I3I is provided with a chamber I35 adapted to receive the housing 5 of the pilot valve P. The wall of the housing section I3I defining the chamber I35 has an end surface I36 (Fig. 13) which engages one side of a gasket I37, and the opposite side of said gasket is engaged with the outer surface of the flange 0 of the housing 5; 'Six bolts I38 project through aligned openings in the sub-base I02, the gasket Hil the base 92, the gasket 4; the flange 5, the gasket I3"! and into threaded openings I39 in the'housi-ng section i3 I to secure the pilot valve P to said housing section.

The rod I26 (Fig. 11') is threaded medially of its length, as indicated at I40 and extends through the diaphragm I33, brass nuts MI and brass plates I42 being arranged upon opposite sides of the diaphragm tosecurely clamp said diaphragm to said rod. The left end of the rod I26 is provided with a series of ridges I 43, which mesh with the teeth ofthe pinion l25 for effecting rotation of the pilot drive shaft 2I'. The housing section BI is provided with a chamber I44 on the pilot valve side of the diaphragm I33 and a passage I45 communicates with said chamber. The outer end of the passage I45 is threaded and a conventional fittin I46 is mounted therein. One end of a conduit I 41 is connected to the fitting I46 and the opposite end I49 of said conduit is connected with th inlet chamber of the valve P.

The housing section I32 is provided with an internally threaded boss I49 into which one end of a brass pipe nipple I50 is threaded and a brass cap I Iis threaded onto the opposite end of said pipe nipple. The rod I26 includes a reduced end portion I52 which projects through an opening I53 in the housing section I32 and into the pipe nipple I50. A washer I54 is carried on the rod end I52 and forms a seat for one end of a compression spring I55. The opposite end of the compression spring I55 seats upon a washer I56 carried on the inner end of an adjusting screw I 51 which projects through a threaded opening I58 in the cap I5I. A lamb nut I59 locks the bolt I51 in the desired position of adjustment.

It will be apparent from Fig. 11 that, as pressure increases in the pipe line L on the inlet side of the valve V, it will be communicated through the tube M1 to the chamber I45 of the pressure-responsive device X and act against the diaphragm I33, tending to flex the same toward the right against the resistance offered by the spring I55. When the pressure in the chamber I45 becomes greater than that for which the spring I55 has been set, the diaphragm I33 will be flexed toward the right and rod I26 will be shifted bodily relative to the pilot valve P to cause clockwise rotation of the pinion 125 and shaft 2| (as viewed in Fig. 12) to position the rotatable pilot element R, to effect opening of the valve V by exhausting operatin fluid from the diaphragm chamber thereof through the tube I 2| and the drain conduit I05. The relation of the rotatable element R with respect to the base plate 92 and the fluid distribution base I02 under such condition is diagrammatically illustrated in Fig. 18. Thus, the exhaust grooves 50, 5| and 52 now register with the ports 95*, 91 and 99*- of the base 92 so that operating fluid under pressure is exhausted from the diaphragm chamber of the main valve V through the conduit I2I and fittin I20, through the passage II9, port II 5, and grooves H3 and H4, in the sub-base I 02, "through the ports 95 91 and 99 in the base 92 and the holes 95, 91 and 99 in the seat 93, through the holes 61, 69 and 'II in the disc 55, thence into the exhaust grooves 50, 5| and 52 in the rotatable element R, then out through the central exhaust port 66 in the disc 55, through the exhaust port 94 in the seat 93, the port 94 in the base 92, the passages 94 and 94 in the base I02, thence through the fitting I04 to be finally discharged through the drain tube I05, whereby to permit opening of the valve V to relieve the pressure in the line L.

As the pressure in the pipe line L is reduced to that for which the sprin I55 of the pressureresponsive device X has been set, said spring will flex the diaphragm I33 toward the left to the position shown in Fig. 11, carrying with it the rod I26 so that the pinion I25 is now rotated count rclockwise to restore the shaft 2| and the rotatable element R. to their initial position in which operating fluid under pressure is admitted to the diaphragm chamber of the main valve 'V through the tube I2I from the pressure chamber I3 of the pilot valve P. The relation of the ports 10 of the rotatable element R. with respect to the ports and passages of the base 92 and sub-base I02 is diagrammatically shown in Fig. 19. It will be noted that the pressure ports 68, I0 and 12 are now aligned with the ports 91*, 99 and 95 respectively, of the base 92. Operating fluid, of

course, will b supplied to the pressure chamber I3 through the tube I09. The flow of operating fluid from the ports 95*, 91 and 99 to the diaphragm chamber of the main valve V will occur through the base I02 but in the reverse direction from that described above for exhaustin spent operating fluid from the diaphragm chamber of said main valve.

It will be noted that the ports 96*, 98 and I00 of the base 92 perform no function when used with a sub-base such as the member I02, but it will be understood that these ports may be active with other forms of sub-bases (not shown).

Fig. 20 illustrates a modified form of base member I60 which may be employed in the pilot valve P shown in Fig. 13 in lieu of the base member 92. The base I60, instead of having a disc sweated to one face thereof, has a seat |6I consisting of a circular stainless steel disc member I 62 pressed into an opening I63 in the base I60. The disc I62 is provided with a central exhaust port I64 and six other ports similar to the ports 95 to I 00 of the disc 92, but only two of these, to wit, ports I65 and I66 being shown. In constructing the base disclosed in Fig. 20, the ports I64, etc., thereof are drilled and the seat I6| is ground, if necessary, and lapped to provide a smooth surface to be engaged by the disc 55 of the rotatable member R.

Th rotatable disc 55 and the seat discs 83, 93 and I62 are made as small as /2 inch in diameter in actual practice and the six equally spaced holes are made as small as inch in diameter and the central exhaust port as small as /32 inch in diameter. The capacity of the pilot valve can, of course, be increased by increasing the size of the parts and ports, but this cannot be done withouta resulting increase in the total fluid pressure forcing the disc 55 against its seat. Such increase in pressure will make it necessary to apply a greater operating force to turn the disc, so that increasing the size of the parts cannot be done without sacrificing sensitive operation of the pilot valve by a very light operating force. The

presentpilot valve with its small disc 55 is very' sensitive and can be rotated by a force as low as two ounces. Hence, the importance of the multiple port arrangement to increase the volume of flow of operating fluid and thereby assure more rapid operation of the devices controlled by the pilot valves P and P without using large parts with their accompanyin high operating force, becomes manifest.

Thus, it will be understood that the exhaust port 66, for example, of the disc 55 (Fig. 5) is of such size that it has a flow capacity about equal to that of the three ports 61, 69 and 'II which communicate therewith through the exhaust grooves 50, 5| and 52. The exhaust port 66 in the base I has a similar large flow capacity. It will also be noted that the exhaust port 94 in the base 92 and the exhaust port 94 in the sub-base I02 are of the larger size. Also, the port H5 in the base member 92 is of the same diameter as the exhaust port 94 Hence, by providing the arcuate grooves I I3 and I I4, in association with the large port 5 and the large exhaust port 94 the capacity of the pilot valve P is greatly increased above what it would be, for example, if only a "I l .-.si. si exhau ero v 1. an a sin l pres ur Z 29 Il er i vid a tawillrbe :und rst tha th detail 41 Qansi iit idn and sor in ar an me ts 9 2116 ilo valv units P- and Pfland the debailspf eqrgstruci an r em th l s nr zrespons v .i rie li i c q e her in :may be mo ied i riqiislr s f tswit e ar nafr mthe-em t the invention.v or -the;sc( )1 )e of the .lann'exed A cornposite member for use iniai pilot .valve and y the like, 7 comprising: a .sheet metal cup? having a bottom Wall provided with at least; on e indyrbi-i ta iinsa s man a mala s prerrly a sa d -.i. r2isss 2i arid b nd d t -t und QbtedfiflvPQtiiQil v ih Out r suflaeaqfsaid b91 Walk-sa d e d 9 me l ab to a an n dr-pv rp fwid nga leas se saw-ro gh sai ,-rotatab -m mber, a l aiiarii gai m an -w mun ea me k s ien- 119i ,iva v 19mP i$i F h us n :means 112%! l ne a, dam r-to emanat n -flu d unde m area-m an er q adii tin q srat ae fluid fiii ili is 'ini i d si e l-cha iib if a fi r li :memiz'e sa ored1i t e i e endq s ida ha a z .a

in atab elemen in sa dtr asur a ber sai rqtai bi i lem iitiii iiidina asheetmeia wpand -a. is a. ais iip ha in a s d Wal and-abet qm awa i i sai .bqttein :wa ha in a r-i lura ty :Q hard p essed el n te de res on .iesmed therein, said depressions merging at a pointaxia la o said bott m wa l, a d di c over yi g s de ression and b in ,.eo. g 31 9 said li inestablis i is a dri in lam na id i i-es ai and sai zrqt l mx b rf .2 iii bei a ial y l ed w th a ea :bod to we t dsam sa dndis Q Qm :wall an l ad d ha i a p rality of po s exteiiin t,

z hrquelysaid la t-mention d po ts re ns .i. enm dia e a de ess ons, andsaid a 5 1213 ax l hurt communicat n wit .e essi ns and .a plurality otexhaust port -sha ed anadi l y omfi dfiii p rt and dis osedini nsi ns; a a v eat fo said s in; m ans rr vide a it pa sae scqoner. i .l 1 pori l fsai dis 3- .A p ot va i-com in r agl ous n rha ine 1a icham e adapted toreceiye on iris-flui d p essu e; a ort d p at m r er seemed t sai musin nd fo min losu ta on 4 o sai h ssure Qham er; qtatabl tailor-mete ber in said pressure chamber including a sheet m ta 9 p and a s sa d cu h v ns a side w a d aimtiqm Well sa d s de-We, ha idea s llzm Me ril Pre s d e on e a a dep es ion; a

notches for-med in th .s'id -v v'all of sa {e the as djpressure p c or said- -exhaust; ,-port-1 ,said disc; and means for -efiecting rotation :of

said. uplin l i ad re ambe h vi p 14.;A '15ilOli alve; omiirising: at-housing having an end Wall atone end thereof and prov-idili ,a chamber foroperatingfluid under-pressure; ,a base member secured-to theoppositeend-of said housing and forming a closure for said pressure chamber; means, for; conducting operating fluid :under pressureitosaidpressure chamber; a shaft extending throughv saidkend wall into said pressure phamber; .a drive member securedlto the inner end-of saidshaftvsaid drive .member 1 having a number or proiectionsformed .01 ts pe ery; a:- otatab1e .e1eme t in .sa d

r s u hamb r a mt table e ement i luding a sheetj metal cup, and 1a disc, said cup,havin'g a side Wall and. a. bottom wall, said bottom wall having three inwardly pressed ,elongated depressi ns iormedtherein, said de e onshe1mgv substantially equally angularly spaced and all-merging at a ,p0i nt,axia11y qfsaidbottom wall, sai'd vdisc overlying said depressions and being secured to said cup member, said side wall of saidcup. having a numberof notches formed therein and pressure ports being disposed intermediate isaid depressions, and said disc having an axial port communicating with said depressions and "three exhaust ports spaced radially from said axial port and disposed intermediate said pressure ports 'each communicating with the outer end portion of one of said depressions, said base member being provided with passages cooperable with the ports of said disc. 7

5. A -pilot valve, comprising: a generally cylindrical sheet metal housing having a side wall with an'end wall atone-endthereof and an outw'ardly extending flange at the opposite end thereof, the portion of said housing intermediate said end wall and flange providing a pressure chamber for operating fluid under pressure and being formed with an outwardly extending shoulder; a sheet metal cap member enclosing said end wall and engaging lsaidshoulder, said end wall and said cap member having aligned passageways; a shaft extending through :said passageways and into said pressurechamber, said side wall of said housing also having an'inwardly extending shoulder; .a guide member for said shaft seated against said last-ementioned shoulder; a drive member secured to they inner end ,of said shaft; aa ;rotatablemember in said pressure chamber arra ged to berotated "bysa-id ,drive member, said rotatable member comprising a sheet metal cup hav-inga bottom wall provided with at least one, inwardly pressed elongated depressi n extendin r d aly o war ly r the center ther of and a disc overly n S i dep ession and secured to sa d our. sa d bottom We an d c h v n al ne por s irc mfe en t al is' s aced rom said depression providin a h o ehmassae thr ugh said rotatable membii 6 il disc also having port means comm-unieating with said depression including a central porteommunicating with the inner end or said depression; and a base member-secured to the flange of said housing an provi ed With pas ag- W fi s iwnerable w h h ports of disc- 6. A pilot valve, comprising: a generally cylindrical sheet metal housing having a side wall with an end Wall at one end thereof and an outwardly extending flange at the opposite end thereof, the @portion of said housing intermediate said end wall and flange providing a pressure chamber for operating fluid under pressure and being formed with an outwardly extending shoulder; a sheet metal cap member enclosing said end wall and engaging said shoulder, said end wall and said cap member having aligned passageways; a shaft extending through said passageways and into said pressure chamber, said side wall of said housing also having an inwardly extending shoulder; a guide member for said shaft seated against said last-mentioned shoulder; a drive member secured to the inner end of said shaft; a rotatable member in said pressure chamber arranged to be rotated by said drive member, said rotatable member comprising a sheet metal cup having a bottom wall provided with at least one inwardly pressed elongated depression extending radially outwardly from the center thereof and a disc overlying said depression and secured to said cup, said bottom wall and disc having aligned ports circumferentially spaced from said depression providing a through passage through said rotatable member, said disc 14 also having port means communicating with said depression including a central port communicating with the inner end of the depression; means connected with said shaft for turning said shaft; and base means secured to said housing and provided with passageways cooperable with the ports of said disc.

DONALD G. GRISWOLD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,121,140 Schoonmaker Dec. 15, 1914 1,829,022 Stevenson Oct. 27, 1931 1,841,453 Rigby Jan. 19, 1932 1,976,417 Steinberg Oct. 9, 1934 2,031,309 Hahn Feb. 18, 1936 2,042,186 Peterson May 26, 1936 2,193,720 Griswold Mar. 12, 1940 2,233,192 Armington Feb. 25, 1941 2,251,481 Corbin Aug. 5, 1941' 2,344,714 Martin Mar. 21, 1944 2,344,913 Ager Mar. 21, 1944 2,861,655 Robinson Oct. 31, 1944 2,399,301 Spence Apr. 30, 1946 

